Surface Global Solar Radiation Research Articles

Examination of potential impacts of future climate change on solar radiation in Togo, West Africa

This study investigates the potential impacts of future warming on Global Solar Radiation (GSR) in different parts of Togo, West Africa. It used regional climate simulations of the International Centre for Theoretical Physics version 4.7 (RegCM4) driven by HadGEM-ES and NorESM-M GCM for three different time-slice periods: baseline (1976–2005), near future (2031–2060) and far future (2070–2099). The models produced realistic simulations of GSR and temperature characteristics over the stations and the simulations spread are within the observation uncertainty. The simulations compared fairly well with the NASA observations. Biases in both the GSR (10–37 Wm−2 or 5–17%) and temperature (0.1–2.0 °C or 0.5–7.3%) were found to be insignificant at p < 0.05 across all the stations under investigation. The results revealed increasing but insignificant trends (0.025–0.043 °C year−1) in observed temperature but decreasing (0.225–0.567 Wm−2 year−1) in GSR during the baseline period. The estimated increasing trends (0.004–0.035% year−1) in cloud cover were partly attributed to the observed variations in surface GSR. All models projected increase in temperature (0.2–4.6 °C) but decrease in GSR (0.5–5.8%) over the entire country at both annual and seasonal time-scales. The simulated future changes in temperatures and GSR were expected to increase further and decrease, respectively, by the end of the century. The study has noteworthy implication in solar photovoltaic power production under warmer climate. It suggests a need for improved technology with the least climate change impacts over the republic of Togo, West Africa.

A 16-year dataset (2000–2015) of high-resolution (3 h, 10 km) global surface solar radiation

Abstract. The recent release of the International Satellite Cloud Climatology Project (ISCCP) HXG cloud products and new ERA5 reanalysis data enabled us to produce a global surface solar radiation (SSR) dataset: a 16-year (2000–2015) high-resolution (3 h, 10 km) global SSR dataset using an improved physical parameterization scheme. The main inputs were cloud optical depth from ISCCP-HXG cloud products; the water vapor, surface pressure and ozone from ERA5 reanalysis data; and albedo and aerosol from Moderate Resolution Imaging Spectroradiometer (MODIS) products. The estimated SSR data were evaluated against surface observations measured at 42 stations of the Baseline Surface Radiation Network (BSRN) and 90 radiation stations of the China Meteorological Administration (CMA). Validation against the BSRN data indicated that the mean bias error (MBE), root mean square error (RMSE) and correlation coefficient (R) for the instantaneous SSR estimates at 10 km scale were −11.5 W m−2, 113.5 W m−2 and 0.92, respectively. When the estimated instantaneous SSR data were upscaled to 90 km, its error was clearly reduced, with RMSE decreasing to 93.4 W m−2 and R increasing to 0.95. For daily SSR estimates at 90 km scale, the MBE, RMSE and R at the BSRN were −5.8 W m−2, 33.1 W m−2 and 0.95, respectively. These error metrics at the CMA radiation stations were 2.1 W m−2, 26.9 W m−2 and 0.95, respectively. Comparisons with other global satellite radiation products indicated that our SSR estimates were generally better than those of the ISCCP flux dataset (ISCCP-FD), the global energy and water cycle experiment surface radiation budget (GEWEX-SRB), and the Earth's Radiant Energy System (CERES). Our SSR dataset will contribute to the land-surface process simulations and the photovoltaic applications in the future. The dataset is available at https://doi.org/10.11888/Meteoro.tpdc.270112 (Tang, 2019).

Global surface solar radiation and photovoltaic power from Coupled Model Intercomparison Project Phase 5 climate models

In this study, historical surface solar radiation (1850–2005) and future photovoltaic power output (2006–2100) are analyzed to investigate the spatial distribution and long-term variation in global solar energy based on the Coupled Model Intercomparison Project Phase 5 (CMIP5) models and the Global Energy Balance Archive (GEBA) database. The results show that global mean surface solar radiation significantly decreased by 0.014 W m−2 year−1 in 1850–2005. According to the Model for Interdisciplinary Research on Climate (MIROC5), surface solar radiation significantly decreased by 3.42 W m−2 year−1 in 1951–1992 and increased by 4.75 W m−2 year−1 in 1993–2005. Global dimming and brightening were observed before and after the 1990s, respectively. The transition of surface solar radiation from dimming to brightening in Europe and the southeastern United States was detected in the 1980s. Stations in Northeast China, Japan, Southeast Africa, the Middle East, and the west coast of India all showed renewed decreasing trends after the 1990s. The direct and indirect effects of anthropogenic aerosols and cloudiness in different periods and regions were the main causes of the changes. To better understand the utilization of global solar energy, global potential photovoltaic power outputs were estimated in future scenarios with an empirical model. Significant increases in potential photovoltaic power are expected in East Asia, Europe, Central Africa and Central America in 2006–2100. The largest increase is expected in central China, where increases are occurring at 3 kWh m−2 year−1. Significantly decreasing potential photovoltaic power is observed in North Africa, the Middle East, Central Asia and Australia. The greatest decrease is observed in the Tibetan Plateau area (approximately −3.0 kWh m−2 year−1 in 2006–2100). With respect to the global distribution of potential photovoltaic power output, large quantities of photovoltaic power are distributed in the northern and southern parts of Africa, the Middle East, the Tibetan Plateau area, the west coasts of North and South America and most of Australia. The yearly mean sum photovoltaic power in these regions is larger than 2000 kW h m−2. Due to the long-term decreasing photovoltaic power (0.67 kWh m−2 year−1) expected worldwide in 2006–2100, effective and rational utilization of solar energy is of great importance.

Effect of dimming of global radiation on morphology and yield of wheat crop in Delhi

Long-term observations of the surface global solar radiation in recent decades have shown a widespread declining trend in many parts of the world. Experient was carried out at the farm of ICARIndian Agricultural Research Institute, New Delhi during rabi season of 2014-15 and 2015-16 to study response of three cultivars (HD 2967, WR 544 and PBW 502) of wheat under five reduced solar radiationlevels (0, 20, 35, 50, 75% shading). Plant height, internode distance and leaf area index (LAI) were measured at different DAS throughout the crop growth period. The result shows that plant height and internode distance increased under 75% shading treatment. The highest leaf area index (LAI) was observed in 35% shading treatment, followed by 20% shading and control. Final biomass, grain yield and harvest index decreased significantly with shading and was lowest in 75% shading treatment. Among the cultivars, HD 2967 performed better under reduced radiation condition as compared to other cultivars.

A new look at solar dimming and brightening in China

AbstractPublished estimates on the magnitude of solar dimming and brightening in China show large discrepancies and inconsistencies in its seasonal variations. A nationwide reorganization of the surface solar radiation (SSR) network during 1990–1993 contributed to these uncertainties, which is reflected in a sudden upward jump in the published composite SSR time series. This jump is found to be prevalent in 23 out of 130 stations due to both natural (7 stations) and operational factors (16 stations). After eliminating the stations containing artifacts and discontinuous records, a new magnitude of solar dimming and brightening was estimated for China, and seasonal trends were determined. A transition from dimming to brightening remains in the SSR trend in China after excluding the affected stations and associated jump, in line with the global SSR trend.

Variability and trends of downward surface global solar radiation over the Iberian Peninsula based on ERA‐40 reanalysis

ABSTRACTA climate study of the incidence of downward surface global solar radiation (SSRD) in the Iberian Peninsula (IP) based primarily on ERA‐40 reanalysis is presented. NCEP/NCAR reanalysis and ground‐based records from several Portuguese and Spanish stations have been also considered. The results show that reanalysis can capture a similar inter‐annual variability as compared to ground‐based observations, especially on a monthly basis, even though annual ERA‐40 (NCEP/NCAR) values tend to underestimate (overestimate) the observations with a mean relative difference of around 20 W m–2 (40 W m–2). On the other hand, ground‐based measurements in Portuguese stations during the period 1964–1989 show a tendency to decrease until the mid‐1970s followed by an increase up to the end of the study period, in line with the dimming/brightening phenomenon reported in the literature. Nevertheless, there are different temporal behaviours as a greater increase since the 1970s is observed in the south and less industrialized regions. Similarly, the ERA‐40 reanalysis shows a noticeable decrease until the early 1970s followed by a slight increase up to the end of the 1990s, suggesting a dimming/brightening transition around the early 1970s, earlier in the south and centre and later in the north of the IP. Although there are slight differences in the magnitude of the trends as well as the turning year of the dimming/brightening periods, the decadal changes of ERA‐40 fairly agree with the ground‐based observations in Portugal and Spain, in contrast to most of the literature for other regions of the world, and is used in the climatology of the SSRD in the study area. NCEP/NCAR reanalysis does not capture the decadal variations of SSRD in the IP. The results show that part of the decadal variability of the global radiation in the IP is related to changes in cloud cover (represented in ERA‐40).

A critical assessment of direct radiative effects of different aerosol types on surface global radiation and its components

A critical assessment of direct radiative effects of different aerosol types on surface global, direct and diffuse radiation is presented. The analysis is based on measurements of aerosol optical properties and surface solar radiation (SSR) of cloud-free days at the Baseline Surface Radiation Network (BSRN) and Aerosol Robotic Network station (AERONET) of Xianghe over the North China Plain between October 2004 and May 2012. Six aerosol types are classified based on aerosol size and absorption from the AERONET retrieval products, including two coarse-mode dominated aerosol types: dust (DU: fine mode fraction (FMF)<0.4) and polluted dust (PD: FMF within 0.4–0.7) and four fine-mode dominated aerosol types (FMF>0.7) but with different single scattering albedo (SSA): highly absorbing (HA: SSA<0.85), moderately absorbing (MA: SSA within 0.85–0.90), slightly absorbing (SA: SSA within 0.90–0.95) and very weakly absorbing (WA: SSA>0.95). Dramatic differences in aerosol direct radiative effect (ADRE) on global SSR and its components between the six aerosol types have been revealed. ADRE efficiency on global SSR for solar zenight angle (SZA) between 55° and 65° ranges from −106Wm−2 for WA to −181Wm−2 for HA. The minimum ADRE efficiency on diffuse SSR is derived for HA aerosols, being 113Wm−2 that is about half of that by DU, the maximum value of six aerosol types. ADRE efficiency on global SSR by DU and PD (−141 to −150Wm−2 for SZA between 55° and 65°) is comparable to that by MA, although 100Wm−2 more direct SSR is extincted by DU and PD than by MA. DU and PD induce more diffuse SSR than MA that offsets larger reduction of direct SSR by DU and PD. Implications of the results to related researches are detailed discussed. The results are derived from aerosol and radiation data in the North China Plain, however the method can be used to any other stations with similar measurements.

Regional long-term trend of ground solar radiation in China over the past 50 years

Based on global solar radiation and related meteorological data from 57 stations in China between 1961 and 2009, we analyze the variation of surface global solar radiation ( G ) and its relationship to meteorological elements using linear-trend estimation, wavelet analysis, and the Mann-Kendall test. The results show that of the 33 stations with time series longer than 45 years, G is significant at the 95% confidence level. G has a decreasing trend at many stations, but results vary across different areas. The decadal departure percentage of G increased from the 1960s to 1970s, declined gradually after the 1970s, and decreased significantly in the 1980s. In the 1990s, the trend at a few sites slightly increased. The trend of cumulative variance is of four types, i.e. rise-fall, rise-fall-slight rise, rise-fall-rise, and not obvious. For changes within a year, the most obvious decline was in winter, and the rest of the year had a slight decrease. The major cycles of annual G were 6-9, 10-13, and 29-33 a. The inflection points were mostly in the 1970s. The reasons for greater changes were complex. Relevant meteorological elements were selected and analyzed by statistical methods. Trends in climatic parameters, such as annual average percentage of sunshine, annual average wind speed, and annual average of low cloud cover, were closely related to G . Thus, this indicated the potential causes of the observed trends in G . The long-term trend for annual G in some regions was also influenced by anthropogenic activities. Annual average percentage of sunshine and annual average wind speed were positively correlated with annual G , respectively.

A simple and efficient algorithm to estimate daily global solar radiation from geostationary satellite data

Surface global solar radiation (GSR) is the primary renewable energy in nature. Geostationary satellite data are used to map GSR in many inversion algorithms in which ground GSR measurements merely serve to validate the satellite retrievals. In this study, a simple algorithm with artificial neural network (ANN) modeling is proposed to explore the non-linear physical relationship between ground daily GSR measurements and Multi-functional Transport Satellite (MTSAT) all-channel observations in an effort to fully exploit information contained in both data sets. Singular value decomposition is implemented to extract the principal signals from satellite data and a novel method is applied to enhance ANN performance at high altitude. A three-layer feed-forward ANN model is trained with one year of daily GSR measurements at ten ground sites. This trained ANN is then used to map continuous daily GSR for two years, and its performance is validated at all 83 ground sites in China. The evaluation result demonstrates that this algorithm can quickly and efficiently build the ANN model that estimates daily GSR from geostationary satellite data with good accuracy in both space and time.

Improving the spatio-temporal distribution of surface solar radiation data by merging ground and satellite measurements

Appropriate information on solar resources is very important for a variety of technological areas, such as: agriculture, meteorology, forestry engineering, water resources and in particular in the designing and sizing of solar energy systems. However, the availability of observed solar radiation measurements has proven to be spatially and temporally inadequate for many applications. In this paper we propose to merge the global solar radiation measurements from the Royal Meteorological Institute of Belgium solar measurements network with the operationally derived surface incoming global short-wave radiation products from Meteosat Second Generation satellites imageries to improve the spatio-temporal resolution of the surface global solar radiation data over Belgium. We evaluate several merging methods with various degrees of complexity (from mean field bias correction to geostatistical merging techniques) together with interpolated ground measurements and satellite-derived values only. The performance of the different methods is assessed by leave-one-out cross-validation.

Parameterizations for the Absorption of Solar Radiation by O2and CO2with Application to Climate Studies

Simple and accurate parameterizations have been developed for computing the absorption of solar radiation due to O2 and CO2. The parameterizations are based on the findings that temperature has a minimal effect on the absorption and that the one-parameter scaling can be applied to take into account the effect of pressure variation along a path. Furthermore, overlapping of the absorption due to CO2 and water vapor is treated accurately in the parameterizations. Simulations with a zonally averaged multilayer energy balance model show that the absorption of solar radiation due to O2 and CO2 has a small, albeit nonnegligible, effect on climate. The global surface solar radiation is reduced by 2.2 W m−2, and the warming of the surface temperature due to a doubled CO2 concentration is reduced by 10% in the Northern Hemisphere. Because the parameterizations can be easily implemented without perturbing other parts of a radiation routine, it is suggested that the absorption of solar radiation by O2 and CO2 be included in climate studies using numerical models.

Radiation Interactions Between Cloud and Snow and Ice Masses

Solar radiation is one of the most important meteorological components in the heat balance of the glaciers and other snow and ice masses. Observed solar radiation values are generally discussed in relation to altitude, landform, geographical position of the observation point and cloud. However, as surface of snow and ice masses possess high albedo, the surface global solar radiation on snow and ice masses usually shows higher value than surrounding ground which is low albedo, due to multiple reflection between surface and cloud. This is an important factor in determination of solar radiation on snow and ice masses. When this process is prominent, surface global solar radiation will depend on the size of the snow and ice masses. This process will be investigated in two parts. One is the presentation of radiation data taken on an ice cap and surrounding ground in the northwestern Tibetan plateau. Observations show that mean daily global solar radiation was 26% higher on the ice cap than on the ground: especially on cloudy days this value exceeded 50%. The second is collaboration of radiation data on snow and ice masses of previous studies: those data will be discussed from the above point of view. The size effect of snow and ice masses on surface solar radiation will be stressed.

Radiation Interactions Between Cloud and Snow and Ice Masses

Solar radiation is one of the most important meteorological components in the heat balance of the glaciers and other snow and ice masses. Observed solar radiation values are generally discussed in relation to altitude, landform, geographical position of the observation point and cloud. However, as surface of snow and ice masses possess high albedo, the surface global solar radiation on snow and ice masses usually shows higher value than surrounding ground which is low albedo, due to multiple reflection between surface and cloud. This is an important factor in determination of solar radiation on snow and ice masses. When this process is prominent, surface global solar radiation will depend on the size of the snow and ice masses. This process will be investigated in two parts. One is the presentation of radiation data taken on an ice cap and surrounding ground in the northwestern Tibetan plateau. Observations show that mean daily global solar radiation was 26% higher on the ice cap than on the ground: especially on cloudy days this value exceeded 50%. The second is collaboration of radiation data on snow and ice masses of previous studies: those data will be discussed from the above point of view. The size effect of snow and ice masses on surface solar radiation will be stressed.

Some Effects of the Yellowstone Fire Smoke Plume on Northeast Colorado at the End of Summer 1988

Abstract Extensive fires in Yellowstone National Park, Wyoming, during the summer of 1988 resulted in considerable smoke transport to surrounding states. The present note provides an observational evaluation of the effects of this plume on (i) surface global solar radiation, (ii) the breakup of the surface nocturnal temperature inversion during the morning, and (iii) surface heating in eastern Colorado. Significant effects in each of these categories are shown.